Background. To address the demand for an increasingly broad spectrum of clinical research activities, we propose a Methodology Core built around the three projects in the MCRC application, and adding to fundamental statistical and epidemiological expertise capabilities in health services and outcomes research, Objectives. The long-range goal of the Methodology Core is to become the focal point for state-of-the-art clinical and translational research in arthritis and musculoskeletal diseases (MSD) locally, regionally and nationally. Towards this vision, the Methodology Core will have four broad objectives: (1) to provide the statistical, epidemiological, outcomes and health services research expertise and leadership required to develop and perform leading-edge clinical research in arthritis and MSD; (2) to support data collection, management, and analytic efforts of the three MCRC projects; (3) to perform and nurture original research in the methodology applicable to clinical research in arthritis and MSD; and (4) to develop new investigator talent in arthritis and MSD. Methods. We have assembled key personnel with expertise in statistics, including statistical genetics, epidemiology, quality of life assessment, quality of care measurement, and economic evaluation. The three MCRC projects, designed by their PIs in collaboration with Methodology Core faculty, illustrate applications of methods in each of the above disciplines. While approximately 80% of requested resources are devoted to directly meeting the design, analysis, and data management needs of the three projects, we will also play a key role in the scientific development program of the MCRC through structured teaching activities, pro-active consultation with research base scientists in the development of new projects, and original contributions to the methods applicable to clinical research in MSD. We have provided two examples of innovative future projects that will be feasible, because of the synergism between content and methodological expertise made possible through the Methodology Core. Included in our applications are mechanisms for prioritization and cost reimbursement for future projects. We have maximized use of existing Centers and scientific capabilities at UAB, thus drawing on a pool of methodologists, which would be impossible to assemble if only MCRC resources were available. Significance. The impact of the Methodology Core will exceed that of the sum of the impacts of the three MCRC projects by virtue of the proposed inter-disciplinary, dynamic infrastructure, which leverages existing resources to advance not only the discovery of new clinical knowledge in arthritis and MSD but also the methods by which it is discovered.